I am looking for some help in modifying a house plan that I recently purchased from one of the major internet sources. We are going to be making several changes to the plan in order to suit the lot and our personal wants. The changes are removing the 3rd garage which decreases the length of the house by 14', making changes to the roof (moving gable), moving some interior walls and a staircase, and increasing the depth of the walkout basement. My builder is old school and thinks we can just mark up the drawings. I would like to have the revisions put on paper to better control materials and costs, and also to prevent costly mistakes. The plan I purchased came in PDF format, it is also available at extra cost in AutoCad. I would appreciate any comments or offers to make these changes from an experienced CA user.